A speed ratio in an automatic transmission for a vehicle is automatically changed according to vehicle speed and throttle opening, but some automatic transmissions have manual shift mode wherein a driver can change the speed ratio manually.
A shifting device for such an automatic transmission is disclosed in U.S. Pat. No. 4,987,792. When the driver intends to apply the manual shift mode, the driver moves a shift lever from the first shift lane to the second shift lane through a changeover lane. In the manual shift mode, when the driver moves the shift lever in an upshift direction from a neutral position, an upshift command is output to the transmission, and when the driver moves the shift lever in a downshift direction from the neutral position, a downshift command is output to the transmission. Whether the shift lever has moved to the second shift lane, or whether the shift lever has moved in the upshift or downshift direction, is detected by plural switches provided in the changeover lane and the second shift lane.
U.S. Pat. No. 5,520,066 discloses a similar shifting device but further comprises a steering switch on the steering wheel for selecting an upshift or downshift operation. By operating this steering switch, the driver can change the speed ratio without operating the shift lever.